using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using TravelCompanyContracts.StoragesContracts;
using TravelCompanyContracts.BindingModels;
using TravelCompanyContracts.SearchModels;
using TravelCompanyContracts.ViewModels;
using TravelCompanyDatabaseImplement.Models;
using Microsoft.EntityFrameworkCore;

namespace TravelCompanyDatabaseImplement.Implements
{
    public class TravelStorage : ITravelStorage
    {
        public List<TravelViewModel> GetFullList()
        {
            using var context = new TravelCompanyDatabase();
            return context.Travels
                    .Include(x => x.Conditions)
                    .ThenInclude(x => x.Condition)
                    .ToList()
                    .Select(x => x.GetViewModel)
                    .ToList();
        }

        public List<TravelViewModel> GetFilteredList(TravelSearchModel model)
        {
            if (string.IsNullOrEmpty(model.TravelName))
            {
                return new();
            }
            using var context = new TravelCompanyDatabase();
            return context.Travels
                    .Include(x => x.Conditions)
                    .ThenInclude(x => x.Condition)
                    .Where(x => x.TravelName.Contains(model.TravelName))
                    .ToList()
                    .Select(x => x.GetViewModel)
                    .ToList();
        }

        public TravelViewModel? GetElement(TravelSearchModel model)
        {
            if (string.IsNullOrEmpty(model.TravelName) && !model.Id.HasValue)
            {
                return null;
            }
            using var context = new TravelCompanyDatabase();
            return context.Travels
                .Include(x => x.Conditions)
                .ThenInclude(x => x.Condition)
                .FirstOrDefault(x => (!string.IsNullOrEmpty(model.TravelName) && x.TravelName == model.TravelName) ||
                                (model.Id.HasValue && x.Id == model.Id))
                ?.GetViewModel;
        }

        public TravelViewModel? Insert(TravelBindingModel model)
        {
            using var context = new TravelCompanyDatabase();
            var newTravel = Travel.Create(context, model);
            if (newTravel == null)
            {
                return null;
            }
            context.Travels.Add(newTravel);
            context.SaveChanges();
            return newTravel.GetViewModel;
        }

        public TravelViewModel? Update(TravelBindingModel model)
        {
            using var context = new TravelCompanyDatabase();
            using var transaction = context.Database.BeginTransaction();
            try
            {
                var travel = context.Travels.FirstOrDefault(rec => rec.Id == model.Id);
                if (travel == null)
                {
                    return null;
                }
                travel.Update(model);
                context.SaveChanges();
                travel.UpdateConditions(context, model);
                transaction.Commit();
                return travel.GetViewModel;
            }
            catch
            {
                transaction.Rollback();
                throw;
            }
        }

        public TravelViewModel? Delete(TravelBindingModel model)
        {
            using var context = new TravelCompanyDatabase();
            var element = context.Travels
                .Include(x => x.Conditions)
                .FirstOrDefault(rec => rec.Id == model.Id);
            if (element != null)
            {
                context.Travels.Remove(element);
                context.SaveChanges();
                return element.GetViewModel;
            }
            return null;
        }
    }
}